Publication:

Role of ultrasound markers in predicting early pregnancy loss: a systematic review

Early pregnancy loss (EPL), defined as pregnancy loss before 13 weeks’ gestation, affects approximately 10–20% of pregnancies and represents a major source of clinical uncertainty within early pregnancy assessment units (EPAUs). Although several ultrasound parameters are routinely measured in early pregnancy, their predictive value for EPL is not consistently applied in clinical practice. A structured review of English-language literature published over the past 10 years was conducted using PubMed, OVID, CINAHL, and Biomed Central databases to evaluate ultrasound markers associated with EPL. Evidence consistently supports predictive value for routinely obtained markers, including crown–rump length (CRL), fetal heart rate (FHR), gestational sac measurements (GSD/MSD), and yolk sac diameter (YSD). Several studies indicate that abnormalities in yolk sac (YS) characteristics and gestational sac (GS) growth may precede changes in FHR or CRL in pregnancies that subsequently miscarry. More recent data refine subchorionic haematoma (SCH) risk stratification, demonstrating a graded association between miscarriage risk and SCH burden expressed as a proportion of GS size, including in assisted reproduction populations. Emerging studies propose gestation-specific predictive thresholds and integrative models using ultrasound indices with or without biochemical markers, while machine-learning and artificial intelligence approaches show high discrimination in selected cohorts. Incorporating routinely measured ultrasound markers into structured early pregnancy assessment may improve counselling and risk stratification, although broader validation is required before advanced predictive models can be adopted routinely.